1. Field of the Invention
This invention relates to a method for manufacturing chromium-bearing pig iron with the use of a blast furnace and, in particular, a method for manufacturing chromium-bearing pig iron, by using -cold bond pellets as a burden with a gas blast from a tuyere in the blast furnace.
2. Description of the Prior Art
Chromium-bearing pig iron is generally manufactured in an electric furnace. Several proposals have been made to manufacture chromium-bearing pig iron in a blast furnace, but are not reduced to actual practices, in spite of being tested in the blast furnace, due to the fact that chromium ore is difficult to reduce and high in its melting point.
Japanese Patent Publication (KOKOKU) No. 60-21218 discloses:
(1) the use of cold bond pellets contained carbon material; and PA1 (2) the use of a high flame temperature at a tuyere nose which is attained by blowing a hot stream of oxygen-enriched air from the tuyere, the air containing oxygen of 41% or less. PA1 introducing cold bond pellets prepared from powdered chrome ore and powdered coke, iron ore and coke lumps into a blast furnace; and PA1 blowing a gas containing more than 50% oxygen, into the blast furnace, through a tuyere therein.
This method has the drawbacks in that a quantity of gas passing through the bosh section is so great that a top gas temperature is high on the order of over 500.degree. C.; this gives a heavy load on the furnace top equipment and involves the low productivity.